Auto Brewery Syndrome: A Rare Presentation of Confusion in Older Adults

Abstract

Confusional states are common in older adults particularly those with underlying medical conditions. Recognizing these condi- tions can be challenging due to the complexity of symptoms. The goal is to identify the clinical signs and symptoms of Auto Brewery Syndrome (ABS) in older adults presenting with confusion and unexplained ethanol levels understanding the role of comorbidities, including immunosuppressed states in the development of ABS and overgrowth of to pathological microorganisms in the gastrointesti- nal tract. Detailed medical history was obtained from a 72-year-old male, who came to the Geriatrics Clinic and multiple presentations at the Emergency Department with confusion, dizziness and falls. Diagnostic workup was negative except for elevated blood ethanol levels during several visits (234 mg/dL, 206 mg/dL, and 159 mg/dL). His comorbidities included stage III squamous cell carcinoma of the larynx treated with surgery and radiotherapy, uncontrolled diabetes mellitus Type 2, hypothyroidism, hypertension, atrial fibrillation, and chronic gastroesophageal reflux disease. Patient consistently denied alcohol consumption. Further workup included stool culture, positive for Candida tropicalis crucial in confirming the diagnosis of ABS after ruling out other causes of confusion and elevated ethanol levels. The patient’s immunosuppressed state likely contributed to Candida over- growth in the gastrointestinal tract and endogenous ethanol produc- tion due to fungal fermentation of carbohydrates in ABS. A course of fluconazole 100 mg daily for three weeks was initiated. ABS is a rare significant cause of confusion in older adults, especially those with complex comorbidities and immunosuppressive conditions. This case emphasizes the importance of identifying the clinical signs of ABS, particularly in patients with unexplained ethanol levels despite deny- ing alcohol consumption. Early recognition and treatment can prevent misdiagnosis and unnecessary interventions. Given the complexity of ABS, increased awareness is essential for clinicians when evaluating patients with unexplained ethanol intoxication, particularly those with immunocompromised states. Pendrey, A., Rodriguez, P., et al. Auto Brewery Syndrome: A Rare Presentation of Confusion in Older Adults. American Geriatrics Society 2025 Annual Scientific Meeting. J Am Geriatr Soc, 73: S120-121. (2025) https://doi.org/10.1111/jgs.19450